Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
PLoS One
2014 Jan 14;91:e85926. doi: 10.1371/journal.pone.0085926.
Show Gene links
Show Anatomy links
CXCR7 is highly expressed in acute lymphoblastic leukemia and potentiates CXCR4 response to CXCL12.
Melo RCC
,
Longhini AL
,
Bigarella CL
,
Baratti MO
,
Traina F
,
Favaro P
,
de Melo Campos P
,
Saad ST
.
???displayArticle.abstract???
Recently, a novel CXCL12-binding receptor, has been identified. This CXCL12-binding receptor commonly known as CXCR7 (CXC chemokine receptor 7), has lately, based on a novel nomenclature, has received the name ACKR3 (atypical chemokine receptor 3). In this study, we aimed to investigate the expression of CXCR7 in leukemic cells, as well as its participation in CXCL12 response. Interesting, we clearly demonstrated that CXCR7 is highly expressed in acute lymphoid leukemic cells compared with myeloid or normal hematopoietic cells and that CXCR7 contributed to T-acute lymphoid leukemic cell migration induced by CXCL12. Moreover, we showed that the cellular location of CXCR7 varied among T-lymphoid cells and this finding may be related to their migration capacity. Finally, we hypothesized that CXCR7 potentiates CXCR4 response and may contribute to the maintenance of leukemia by initiating cell recruitment to bone marrow niches that were once occupied by normal hematopoietic stem cells.
???displayArticle.pubmedLink???
24497931
???displayArticle.pmcLink???PMC3908922 ???displayArticle.link???PLoS One
Figure 1. Schematic model of flow cytometric analysis.A) An FSC/SSC gate and anti-CD45+/SSC was created around the viable lymphocyte population for further analysis of CD3+CD4+, CD3+ CD8+ subsets and CD19+ cells. B) An FSC/SSC and anti-CD45+/SSC gates were created around the viable granulocyte population for further analysis of CD14+ cells and CD16+ cells.
Figure 3. CXCR7 positively correlates with the percentage of blasts in the bone marrow.Correlation of log-transformed relative expression of CXCR7/HPRT-GAPDH and the percentage of blasts in the bone marrow of MDS, AML and ALL patients showed CXCR7 expression levels to be positively correlated with bone marrow blast counts (P = 0.004). Two-tailed Spearman’s correlation. The number of individuals is shown in the figure.
Figure 4. Higher expression of CXCR7 in T-acute lymphoid leukemia lines MOLT4 and Jurkat.A) Western blot analysis of CXCR7 protein levels in myeloid (U937, P39, K562 and KG-1), B-lymphoid (Daudi, Raji) and T-lymphoid (MOLT4 and Jurkat) cell lines. Total cell extracts were blotted with antibodies against CXCR7 (42 kDa), CXCR4 (42 kDa) or β-actin (42 kDa), as a control for equal sample loading, and developed with the ECL Western Blot Analysis System. CXCR7 protein was detectable in all acute leukemia cell lines; however CXCR7 was more expressed in the T-acute lymphoid cell lines MOLT4 and Jurkat when compared to other cell lines. CXCR4 proteins levels were homogeneous in all cell lines analyzed. B) Quantitative expression of CXCR7 mRNA in leukemic cells lines. mRNA expression levels of CXCR7 were normalized by HPRT and GAPDH endogenous control. CXCR7 mRNA was more expressed in T-acute lymphoid cell lines MOLT4 and Jurkat when compared to other cell lines.
Figure 5. Different localizations of CXCR7 in MOLT4 cells and in Jurkat cells.CXCR4 has the same cellular localization (cell surface and intracellular) in both cell lines. (A–B) Confocal micrographs of MOLT4 and Jurkat cell lines displaying CXCR7 (green) and CXCR4 (red) staining using 63× oil immersion objectives. Appropriated markers for membrane and cytoplasm were used to confirm the localization of these receptors: E-cadherin and Op18 present (yellow), respectively, in the membrane and in the cytoplasm. CXCR7 showed colocalization with these proteins in both cell lines; however CXCR7 was located mainly on the cell surface of MOLT4 cells; unlike, in Jurkat cells, where CXCR7 presented an intracellular and cell surface localization. CXCR4 had same cellular distribution (cell surface and intracellular) in both cell lines. (B) Flow Cytometry, a more quantitative method, confirmed the results observed in confocal microscopy because showed that less than 2% of MOLT4 cells versus 67% of Jurkat cells displayed intracellular CXCR7.
Figure 6. Lentivirus-mediated shRNA targeting CXCR7 effectively silenced CXCR7 in MOLT4 and Jurkat cells.A) Quantitative expression of CXCR7 mRNA in cells relative to the shControl cells. mRNA expression levels of CXCR7 were normalized by HPRT and GAPDH endogenous control. Results were analyzed using 2−ΔΔCT. CXCR7 mRNA expression was reduced in MOLT4 cells (41%) and Jurkat cells (63%) when compared with shControl cells. (B) Western blotting analysis of shControl and shCXCR7 cell extracts. The membrane was blotted with antibodies against CXCR7 (42 kDa) or GAPDH (37 kDa), as a control for equal sample loading, and developed with the ECL Western Blot Analysis System. The bar graphs represent the band intensity of CXCR7 protein expression corrected for loading differences based on the corresponding GAPDH bands (UN-SCAN-IT software). Protein levels of CXCR7 were also reduced in MOLT4 cells (63%) and Jurkat cells (74%) when compared with shControl cells.
Figure 7. CXCR7 silencing decreases MOLT4 and Jurkat cell migration.Cell migration toward either RPMI with 0.1% BSA and RPMI or 0.1% BSA containing CXCL12 (200 ng/mL) used as negative control and chemoattractant, respectively. After 4 h, the number of migrated cells was counted and was expressed as a percentage of the input, i.e., the number of cells applied directly to the lower compartment in parallel wells. The migration of cells was normalized to 100% +/− sd of triplicates. (A) The CXCR7 silencing resulted in significant changes in MOLT4 chemotactic response (P = 0.0159). The inhibition of CXCR4-dependent chemotaxis by its antagonist AMD3100 (1.25 µg/mL) promoted a similar effect (P = 0.0159). Moreover, the silencing of CXCR7 plus the treatment with AMD3100 exhibited a synergistic effect in cell chemotactic capacity (P = 0.0086). (B) The same effect was observed with Jurkat cells. The CXCR7 silencing (P = 0.0366) or the inhibition of CXCR4-dependent chemotaxis by its antagonist AMD3100 (P = 0.019) reduced Jurkat chemotactic response. The simultaneous silencing of CXCR7 and treatment with AMD3100 also exhibited a synergistic effect upon cell chemotactic capacity (P = 0.0191); Mann-Whitney test.
Figure 8. CXCR7 silencing did not modify apoptosis and proliferation of MOLT4 and Jurkat cells.To evaluate whether CXCR7 is important in the process of cell death, control and inhibited CXCR7 cells were exposed to 10 J/m2 UV for different periods of time (0, 3, and 6 hours) and apoptosis was detected by flow cytometry using Annexin V/PI staining method. Cell proliferation was determined by MTT assay. Results are shown as mean ±SD of six replicates. No differences in apoptosis rate (A) or proliferation (B) were observed in MOLT4 and Jurkat cell lines.
Figure 9. High CXCR7 expression of peripheral blood and bone marrow lymphocytes.(A) CXCR7 is expressed in peripheral blood leukocytes, however an increase in CXCR7 cell surface expression was observed in lymphocytes compared to monocytes and neutrophils. This difference was more apparent and significant when the cells were permeabilized (lymphocytes vs. monocytes, P = 0.0265 and lymphocytes vs. neutrophils, P = 0.0286) showing that the localization of this receptor is mainly intracellular in B-lymphocytes, CD4+ T-lymphocytes and CD8+ T-lymphocytes; Mann-Whitney test.
Bachelerie,
International Union of Basic and Clinical Pharmacology. [corrected]. LXXXIX. Update on the extended family of chemokine receptors and introducing a new nomenclature for atypical chemokine receptors.
2014, Pubmed
Bachelerie,
International Union of Basic and Clinical Pharmacology. [corrected]. LXXXIX. Update on the extended family of chemokine receptors and introducing a new nomenclature for atypical chemokine receptors.
2014,
Pubmed
Balabanian,
The chemokine SDF-1/CXCL12 binds to and signals through the orphan receptor RDC1 in T lymphocytes.
2005,
Pubmed
Berahovich,
CXCR7 protein is not expressed on human or mouse leukocytes.
2010,
Pubmed
Bigarella,
ARHGAP21 modulates FAK activity and impairs glioblastoma cell migration.
2009,
Pubmed
Boldajipour,
Control of chemokine-guided cell migration by ligand sequestration.
2008,
Pubmed
Boudot,
Differential estrogen-regulation of CXCL12 chemokine receptors, CXCR4 and CXCR7, contributes to the growth effect of estrogens in breast cancer cells.
2011,
Pubmed
Broustas,
Rad9 protein contributes to prostate tumor progression by promoting cell migration and anoikis resistance.
2012,
Pubmed
Burger,
CXCR4: a key receptor in the crosstalk between tumor cells and their microenvironment.
2006,
Pubmed
Burger,
The CXCR4 chemokine receptor in acute and chronic leukaemia: a marrow homing receptor and potential therapeutic target.
2007,
Pubmed
Burns,
A novel chemokine receptor for SDF-1 and I-TAC involved in cell survival, cell adhesion, and tumor development.
2006,
Pubmed
Butler,
Involvement of calpain in the process of Jurkat T cell chemotaxis.
2009,
Pubmed
Ceradini,
Progenitor cell trafficking is regulated by hypoxic gradients through HIF-1 induction of SDF-1.
2004,
Pubmed
Cinamon,
Shear forces promote lymphocyte migration across vascular endothelium bearing apical chemokines.
2001,
Pubmed
Colvin,
Intracellular domains of CXCR3 that mediate CXCL9, CXCL10, and CXCL11 function.
2004,
Pubmed
Cruz-Orengo,
CXCR7 influences leukocyte entry into the CNS parenchyma by controlling abluminal CXCL12 abundance during autoimmunity.
2011,
Pubmed
Décaillot,
CXCR7/CXCR4 heterodimer constitutively recruits beta-arrestin to enhance cell migration.
2011,
Pubmed
Faaij,
Chemokine/chemokine receptor interactions in extramedullary leukaemia of the skin in childhood AML: differential roles for CCR2, CCR5, CXCR4 and CXCR7.
2010,
Pubmed
Favaro,
FMNL1 promotes proliferation and migration of leukemia cells.
2013,
Pubmed
,
Echinobase
Grymula,
Overlapping and distinct role of CXCR7-SDF-1/ITAC and CXCR4-SDF-1 axes in regulating metastatic behavior of human rhabdomyosarcomas.
2010,
Pubmed
Hartmann,
A crosstalk between intracellular CXCR7 and CXCR4 involved in rapid CXCL12-triggered integrin activation but not in chemokine-triggered motility of human T lymphocytes and CD34+ cells.
2008,
Pubmed
Kucia,
CXCR4-SDF-1 signalling, locomotion, chemotaxis and adhesion.
2004,
Pubmed
Lagane,
Mutation of the DRY motif reveals different structural requirements for the CC chemokine receptor 5-mediated signaling and receptor endocytosis.
2005,
Pubmed
Levoye,
CXCR7 heterodimerizes with CXCR4 and regulates CXCL12-mediated G protein signaling.
2009,
Pubmed
Li,
The expression of CXCR4, CXCL12 and CXCR7 in malignant pleural mesothelioma.
2011,
Pubmed
Lodowski,
Chemokine receptors and other G protein-coupled receptors.
2009,
Pubmed
Luker,
Imaging chemokine receptor dimerization with firefly luciferase complementation.
2009,
Pubmed
Mahabaleshwar,
Killing the messenger: The role of CXCR7 in regulating primordial germ cell migration.
2008,
Pubmed
Maksym,
The role of stromal-derived factor-1--CXCR7 axis in development and cancer.
2009,
Pubmed
Mazzinghi,
Essential but differential role for CXCR4 and CXCR7 in the therapeutic homing of human renal progenitor cells.
2008,
Pubmed
Mellado,
Chemokine receptor homo- or heterodimerization activates distinct signaling pathways.
2001,
Pubmed
Miao,
CXCR7 (RDC1) promotes breast and lung tumor growth in vivo and is expressed on tumor-associated vasculature.
2007,
Pubmed
Miller,
CXCR4 signaling in the regulation of stem cell migration and development.
2008,
Pubmed
Mizoguchi,
Sdf1/Cxcr4 signaling controls the dorsal migration of endodermal cells during zebrafish gastrulation.
2008,
Pubmed
Monnier,
CXCR7 is up-regulated in human and murine hepatocellular carcinoma and is specifically expressed by endothelial cells.
2012,
Pubmed
Naumann,
CXCR7 functions as a scavenger for CXCL12 and CXCL11.
2010,
Pubmed
Ottoson,
Cutting edge: T cell migration regulated by CXCR4 chemokine receptor signaling to ZAP-70 tyrosine kinase.
2001,
Pubmed
Peled,
The chemokine SDF-1 activates the integrins LFA-1, VLA-4, and VLA-5 on immature human CD34(+) cells: role in transendothelial/stromal migration and engraftment of NOD/SCID mice.
2000,
Pubmed
Peled,
The chemokine SDF-1 stimulates integrin-mediated arrest of CD34(+) cells on vascular endothelium under shear flow.
1999,
Pubmed
Rajagopal,
Beta-arrestin- but not G protein-mediated signaling by the "decoy" receptor CXCR7.
2010,
Pubmed
Shimizu,
CXCR7 protein expression in human adult brain and differentiated neurons.
2011,
Pubmed
Sierro,
Disrupted cardiac development but normal hematopoiesis in mice deficient in the second CXCL12/SDF-1 receptor, CXCR7.
2007,
Pubmed
Smart,
The stem cell movement.
2008,
Pubmed
Tarnowski,
Regulation of expression of stromal-derived factor-1 receptors: CXCR4 and CXCR7 in human rhabdomyosarcomas.
2010,
Pubmed
Tarnowski,
CXCR7: a new SDF-1-binding receptor in contrast to normal CD34(+) progenitors is functional and is expressed at higher level in human malignant hematopoietic cells.
2010,
Pubmed
Thelen,
Dancing to the tune of chemokines.
2001,
Pubmed
Thelen,
CXCR7, CXCR4 and CXCL12: an eccentric trio?
2008,
Pubmed
Traina,
BCR-ABL binds to IRS-1 and IRS-1 phosphorylation is inhibited by imatinib in K562 cells.
2003,
Pubmed
Wang,
The role of CXCR7/RDC1 as a chemokine receptor for CXCL12/SDF-1 in prostate cancer.
2008,
Pubmed
Werner,
Reciprocal regulation of CXCR4 and CXCR7 in intestinal mucosal homeostasis and inflammatory bowel disease.
2011,
Pubmed
Yao,
High expression of CXCR4 and CXCR7 predicts poor survival in gallbladder cancer.
2011,
Pubmed
Yoshida,
Signalling pathway mediated by CXCR7, an alternative chemokine receptor for stromal-cell derived factor-1α, in AtT20 mouse adrenocorticotrophic hormone-secreting pituitary adenoma cells.
2009,
Pubmed
Zabel,
The novel chemokine receptor CXCR7 regulates trans-endothelial migration of cancer cells.
2011,
Pubmed